All-Metal Wheels of the VIPER Moon Rover Spin for 25 Miles in “High-Tech Sandbox”


Come 2023, NASA will be launching a Moon mission with a clear goal in mind: find water at the lunar South Pole. The mission is centered around an exploration robot called Volatiles Investigating Polar Exploration Rover, or VIPER. Back in October, the American space agency announced it cleared the design of its first lunar mobile robot, as in this one, unlike the Boeing-made Lunar Roving Vehicle of the Apollo program, will be made by NASA itself. That meant construction of the rover could begin and voila, just three months have passed and we’re getting the first glimpse of one of the most important elements of the rover: the wheels. Just like most other rovers designed for alien world exploration, VIPER will use all-metal wheels with no rubber wrapped around them. That makes them particularly robust at handling the harsh terrain on the Moon, but also means they have to endure stresses far beyond what regular wheels have to endure. To see how they cope, NASA tested the wheels for three weeks in an indoor “Moon-mimicking set-up.” That was in essence a 20-foot-long (6 meters) sandbox filled with lunar soil simulant, measuring devices, cameras, and robotic controls. During that time, they spun for the equivalent of about 25 miles (40 km), being subjected to all kinds of tests, from going up slopes to experiencing wheel slip and going over rocks and other simulated obstacles. In all, 196 scenarios of different rock shapes, heights, and positions the rover were designed to test the wheels. Using control software put together by a company called ProtoInnovations, the hardware performed as expected, according to Arno Rogg, rover mobility system engineer at NASA. “At the end of the test, both its physical condition and its behavior – looking especially at its traction – were only slightly degraded compared to when we started the test. By driving the wheel more than twice the distance it’s expected to travel on the lunar surface, we reduced the risk of any premature wheel failure occurring on the Moon,” the engineer said in a statement. VIPER is the size of a golf cart and weighs 600 pounds (272 kg). It will be sent in the general area where the first Artemis astronauts will land in a bid to open in-situ resource utilization (ISRU) opportunities for a potential extended human presence on the surface.